Field of the Invention
An embodiment of this invention relates to control apparatus for estimating operating parameter of a gas-turbine aeroengine.
Description of the Related Art
A gas-turbine aeroengine is typically equipped with at least a high-pressure turbine rotated by injection of high-pressure gas produced upon ignition and combustion of an air-fuel mixture in a combustion chamber and with a low-pressure turbine located downstream of the high-pressure turbine to be rotated by low-pressure gas exiting the high-pressure turbine. Such a gas-turbine aeroengine is provided with sensors or detectors for detecting numerous operating parameters used to control the engine, including a low-pressure turbine rotational speed N1, a high-pressure turbine rotational speed N2, and an outlet pressure P3 of a high-pressure compressor connected to the high-pressure turbine.
As the control is disturbed by abnormalities arising in these sensors, each or a relatively important one of the sensors is preferably monitored for malfunctioning by estimating (calculating) the operating parameter based on the output(s) of the other sensor(s) and comparing the estimated operating parameter with the outputs of the sensor(s).
Therefore, as taught by Japanese Laid-Open Patent Application No. 2006-9684 (Patent Document 1), it has been proposed to use the relationship between the outputs of the high-pressure turbine rotational speed sensor and an intake air temperature sensor to calculate an estimated value of the low-pressure turbine rotational speed N1 as an operating parameter and to discriminate the normality of the low-pressure turbine rotational speed sensor by comparing the calculated operating parameter with the output of the low-pressure turbine rotational speed sensor.